1. Field of the Invention
DNA can be amplified from human red blood cell samples by primers designed from DNA sequences encoding a bacterial major surface protein and 16 s ribosomal RNA (16s rRNA). Primer pairs based on DNA sequences for the major surface protein 2 (MSP2) of Ehrlichia/Anaplasma can amplify DNA homologous to DNA from human chromosomes 1 and 7 from red blood cell samples. Primers based on DNA sequences encoding 16s rRNA from Anaplasma species can amplify DNA from human red blood cells, but not from nucleated white blood cells. The amplified DNA is contained in samples of red blood cells from HIV infected individuals as well as from some healthy individuals of Caucasian or African origin and represents a risk factor for HIV infection. These primers can be employed in methods for assessing risk of HIV infection by amplifying DNA from red blood cell samples.
2. Description of the Related Art
Chronic HIV infection causes strong immune depression (AIDS) in most patients leading to lethal opportunistic infections or cancers. Specific inhibitors of HIV multiplication are currently used for treating HIV infected patients before they reach the full-blown stage of AIDS. Such inhibitors act mostly on the reverse transcriptase and protease of HIV to efficiently suppress virus multiplication and reduce virus load to a low level of less than 40 viral RNA copies per ml of blood. Treatment results in a partial recovery of the patient's immune system as evidenced by an increase of CD4 lymphocytes and reduction of or lessened severity of opportunistic infections. However, this treatment has to be given without interruption in order to prevent rebound of virus multiplication and a subsequent reduction in the numbers of CD4 lymphocytes. Rebound of viral infection is evidence of a reservoir of HIV in infected patients that is not accessible to antiviral treatment and the existence of this reservoir is generally acknowledged. In addition to a reservoir of HIV in infected patients, such patients often carry other microorganisms that are associated with HIV infection or that cause opportunistic infections.
Microorganisms associated with HIV infection that are detectable in human red blood cells, but not in human leukocytes or other kinds of nucleated human cells have not been previously characterized. The identification and characterization of microorganisms associated with HIV infection is of interest for purposes of assessing risk of HIV infection or determining the status of an HIV infected patient, for assessing risk or status of opportunistic infections, and to evaluate modes of treatment for HIV infected subjects.